Time travelling

Of course we can fantasise, but we can also fantasise about purple aliens that want to steal all bananas from earth, it's just very very very unlikely that travelling into the past is possible just like to the future is possible.

I think when some people heard about time relativity and going the future they found it logical time travelling to the past is also possible. This is very simplistic, and trying all theories out on this subject just for a slight chance of it being possible is not based on anything.

Timeflow goes from >0 to max, it can not be 0 and it can not be less than 0 either.
Besides this, you only change YOURSELF if you travel to the future, the world around you is unaffected.

When is zero? How can you be sure time isn't infinite in both tenses?

well theres a law of some thing or rather, but if projectory ABC is allowed my physics in that situation then projectory CBA is compulsory.

Originally posted by xenophanes85
When is zero? How can you be sure time isn't infinite in both tenses?

Zero would be when your accelaration and speed are so high, time stops.
But the thing is, time can never stop. You can bend time a little bit, slowing it down but you can't disable it by making it stop.
Getting time to go backwards would require you to go over that point where time stops, but this point can never be reached.
The closer you get to "no time advance", the harder it is to slow down time even more.
It's like a 1/X function, never reaching 0.

The energy put into reaching a higher speed, will always translate into either more distance per time or less time per distance.
It's just the MPH situation, when the M is at its max, the H will go down, making speeds above the speed of light possible.

[Edited on 2-5-2004 by Jakko]

physics.syr.edu...

simple visualization of lorentzian vs. galilean time window.

what part does metabolism/neurology/genetics play? observers are made of blood and bones and guts. to bypass physics/enginnering problems of time dilation experiments on earth- if those mcgill kids ever crack the chemistry of time perception then it could lead to very bizarre and dangerous things.. time travel drugs? did phillip dick write about that? what a cracked idea. wrong also unless it is more complicated than cryogenics or total recall- ie physical change observable to both the subject and observer. we already move at different speeds. some hardly at all.

xenophanes85 some good ideas.... well, Star trek is great for the imagination, but bad on science. my first question about the warp drive that i would like to know... how do they go from 0 to warp 3 without slamming everyones body to death on the acceleration. :-) Well back to the topic... :-)

time Travel... 2 theories.. well, they are not very likely, but they are valid.

1. This came from Mr. van Stockman in Scotland. he has proven that time could be altered. Of course you would have to have an infinately long cylinder rotating on an infinately long axis. But, through relativity itself, if a massive object that large would sping, it would actually drag not only space, but time as well. So, if you got in your space spice and encircled it, then time travel would actually be possible. well, mathmatically, it is neat, but, realistically, how could you build an infinately long cylinder. hmmm.. But, brings to light the idea of possibility itself.

2) My favorite..... Wormholes... yes, wormholes... OK, so no one knows for sure if they exist or not, but they have been proven to be a possibility through general relativity. It has also proven that wormholes could in fact be not only a shortcut through space, but also a shortcut through time. without going to much into the details of wormholes, we will just say that they are tunnels of nothingnes.. the grade school explanation.. ha ha well, if we were to open up a wormhole and travel at light speen.. well, it is actually 99.99999 5 as 100% is not an otion :-) We.. travel for a few hours with someone on the other end keeping communication. They keep talking and the person gets to the destination. Ok, no suprises, they are still in communication. well, the traveler heads back to earth... but, when he gets back it is now some few million years or so in the future. But, he is still in communication with the past. when he lands, the person he is communicating with cannot see him, the reason is that he has kept the time whole open, but has stayed in the present .. basically some many many years in the future. now, if he could harness that wormhole and enter it, theoretically he could go back to the past. this concept was developed at CIT. California Institute of technology.. I think by a mr. Thorpe or something like that.

But, this takes me back to my point before. time travel to the past may be technically out of our reach,,,, maybe forever, but it is not impossible. well, at least until the first time machine is built.

Also, another idea..... maybe we have been visited by future travelers..... of course, they would probably be locked up in an institute.... ha ha trust me, i came from the future.... ;-)

Just some thoughts to ponder.....

-once again-

1. Time travelling using time relativity (the only known valid way to manipulate time) means manipulating the one object/serie of objects by changing the timeflow for those objects.
You can not manipulate the whole world around you.

2. Time manipulation is not possible in both directions, you can only make time go slower for the object you are manipulating/time go faster for all around the object you are manipulating.
you can not slow down time enough to make it stop or become negative

I meant when did time begin? When is time itself's 0? What are we counting up from? When is the present?Time being infinite in the future is a given. If time is infinite in the past as well as the future, when would that make the present? We are going to have to answer this question before time travel is invented. If its zero, we can figure that out. If its infinite, we cannot since there would be no starting point to count up from. Which means we cant count backwards to the past or forwards to the future. The time machine in Back to the Future for example, used the Gregorian calendar as points of destination. But you dont have to be a rocket scientist to know that the calendar sysytem we use is a human invention. All time doesn't follow this, weather it started at 0 or infinity. Say we 'type' June 3 1985 into the time machine. We wont end up on the June 3 1985 we know, but rather some time during well, time. Do you understand what I am trying to say?

[Edited on 5-2-04 by xenophanes85]

hmm.. i thought time cud b described as our "4th dimension" of our universe? The other 3 dimensions r up, down, foward and backwards (the last 2 r in the same dimension); time cannot exist witout space and space cannot exist without time, and it is this relationship that is called the space-time continium, which means that any event that occurs in the universe has to involve both space and time.

If you accept the Big Bang, or some variant of it, and if you accept relativity and quantum mechanics, or some variant of them, then spacetime began at the Big Bang. The Big Bang would be time zero. If you also subscribe to the one universe point of view, then the Big Bang would be an absolute time zero.

If you believe in an eternal god, then there is no absolute time zero, and the Big Bang time zero might or might not hold true locally for our universe.

Originally posted by freedom_88
hmm.. i thought time cud b described as our "4th dimension" of our universe? The other 3 dimensions r up, down, foward and backwards (the last 2 r in the same dimension); time cannot exist witout space and space cannot exist without time, and it is this relationship that is called the space-time continium, which means that any event that occurs in the universe has to involve both space and time.

Although time can be seen as another dimension, I do have a problem with it being described as another kind of spatial dimension. Special relativity makes an enormous distinction between time and the three spaces dimension in the metric tensor. Basicly it says that if you want to calculate the 'seperation' between two points you use:

s2 = -t2 + x2 + y2 + z2

Time gets a minus, while the space dimensions don't get one. Because you deal with the metric tensor a lot in relativity, there is a enormous difference between working with time and the three space dimensions.

I think this should be added to most science books that simply want to treat time as another spatial dimension.

The folowing question must be asked and answered, when did the Big-Bang take place?

If you believe Time is a concept NOT a dimension, I think Time always has existed (meaning infinite). When the Big-Bang happened, Space was created. Space became a way to measure Time. The two together became the 4th dimension.

[Edited on 5-2-04 by xenophanes85]

Originally posted by xenophanes85
The folowing question must be asked and answered, when did the Big-Bang take place?

I think Time always has existed (meaning infinite). When the Big-Bang happened, Space was created. Space became a way to measure Time.

[Edited on 5-2-04 by xenophanes85]

Hmm, I think your question can be answered based on current popular theory:

1. The Big Bang began time and space so it happened at the beginning of time.

2. Scientists who know how can use observation to count back from now to the beginning, and thus give us an age for the universe. Right now I think the age of the universe is suppose to be between 12 and 15 billion years. So the Big Bang took place 12 to 15 billion years ago.

Well, I believe they will forever just keep on finding older and older stars, planets, sectors of Space, etc as time goes on. In other words, they will never find a 'common age' of Space, a place where things don't get older, which means that the Universe, Space, Time, and Space-Time truly are infinite.

[Edited on 5-2-04 by xenophanes85]

Originally posted by xenophanes85
Well, I believe they will forever just keep on finding older and older stars, planets, sectors of Space, etc as time goes on. In other words, they will never find a 'common age' of Space, a place where things don't get older, which means that the Universe, Space, Time, and Space-Time truly are infinite.

[Edited on 5-2-04 by xenophanes85]

They don't measure the age of the universe by finding older and older stars, planets, whatever. They calculate the age of the universe using the rate of expansion. Here's a link to a good explanation:

science.nasa.gov...

Ok, so without reading the Theory of Expansion, the oldest things aren't in the center (did not use 'edge' on purpose) of the Universe while the newest things are still being created in the center of the Universe, wherever that is? As they continue to look into Space, they will either find:

1. Things younger than they have found before (things near the center)
   
2. Things older than they have found before (things near the opposite of the center)
   

Depending if they look at the expanding part of the Universe or to the center. If its older, that means it came from somewhere or some time - everything was created somehwere in Time. So it would follow that the deeper and deeper into space we can see, the older and older things will get, meaning the farther and farther in the past they were created. If they see things getting older and older, infinitely into the future, that means that time in the past is infinite too. Confusing. Crap, I wish I were smart enough to explain what I believe.

[Edited on 5-2-04 by xenophanes85]

WRONG BIG TIME......RELATIVITY AND QUANTUM MECHANICS ARE PHYSICALLY EXPERIMENTAL FACTS!!! YOU NEED TO KEEP UP WITH MODERN SCIENCE....YOU GUYS MAKE BLIND STATEMENTS IN THE REALM OF PHILOSOPHY WHEN IT COMES TO TIME THEORY......DO YOUR RESEARCH....DONT THROW IGNORANT OPINIONS AT PEOPLE WHO HAVE THE DEGREES, DONE THE EXPERIMENTS, AND VERIFED THE PHYSICAL REALITY!!!!

IF YOU HAVE NOT SPENT YOUR LIFE STUDYING A TOPIC OF SCIENCE DONT GUESS AT AN ANSWER!!!

YOU CLEARLY DO nOT HAVE A DEGREE IN PHYSICS

Originally posted by Phaselink
... IF YOU HAVE NOT SPENT YOUR LIFE STUDYING A TOPIC OF SCIENCE DONT GUESS AT AN ANSWER!!!

YOU CLEARLY DO nOT HAVE A DEGREE IN PHYSICS

LOL ... how sad ... this guy doesn't even know science itself, especially time related issues, is based on guess work. Ever hear of a Hypothesis (guess work)? They turn into Theories (experimental stage), which turn into Laws (proven fact) - and I haven't heard of the LAW of Space-Time, or the LAW of Relativity ... have you? Maybe in your uncontrollable fits of anger like above, you make your own Laws, but basically, there are no absolutes in the unknown.

You my freind, clearly do not have a degree in physics either. Maybe a degree in capitalization issues though.

[Edited on 5-2-04 by xenophanes85]

Originally posted by xenophanes85
Ok, so without reading the Theory of Expansion, the oldest things aren't in the center (did not use 'edge' on purpose) of the Universe while the newest things are still being created in the center of the Universe, wherever that is? As they continue to look into Space, they will either find:

1. Things younger than they have found before (things near the center)
   
2. Things older than they have found before (things near the opposite of the center)
   

Depending if they look at the expanding part of the Universe or to the center. If its older, that means it came from somewhere or some time - everything was created somehwere in Time. So it would follow that the deeper and deeper into space we can see, the older and older things will get, meaning the farther and farther in the past they were created. If they see things getting older and older, infinitely into the future, that means that time in the past is infinite too. Confusing. Crap, I wish I were smart enough to explain what I believe.

[Edited on 5-2-04 by xenophanes85]

I think you are plenty smart. But you really need to read the link. I'm sure you will be able to understand it. If you don't read it, you won't know enough about it to take account of it as you think about and discuss these things.

Again, measuring the age of the universe has nothing to do with finding older and older things. The measurement is based on the rate of expansion, as I said before.

Originally posted by xenophanes85
LOL ... how sad ... this guy doesn't even know science itself, especially time related issues, is based on guess work. There are no absolutes in the unknown. You my freind, clearly do not have a degree in physics either. Maybe a degree in capitalization issues though.

Why do you think science is based on guess work?